For many gardeners, summer is the most rewarding part of their work. It’s over this three month period that gardeners watch their well-tended plants produce blooms that turn into sweet strawberries, tomatoes, or zucchini, or their flowers burst into a kaleidoscope of colors. Unfortunately, summer doesn’t always have our plants’ best interests in mind. Long hot spells can wreak havoc on vegetables, flowers, bushes, grasses, and trees alike, and climate change is unlikely to be in our favor in the next decades.
So what can you do?
The best way to protect your plants from summer heat is to be prepared, and the first step is knowing what to watch for. Plants have the ability to tolerate heat better later in the season, but early heat waves can damage, and in some cases, kill, an entire crop.
Here are just a few problems that heat can bring:
Wilting
Wilting occurs when plants don’t have enough water in their roots to supply their leaves. Hot days—or transplanting—may cause wilting as plants don’t have the available water reserves.
Bolting
If the most rewarding part of growing a vegetable garden is enjoying the literal fruits of your labor, then the worst is seeing those same fruits grow past the point of enjoyment. Bolting, the result of plants skipping their harvest season in order to produce seeds for the next generation of plants, is most common in vegetables and typically associated with high heat.
Dropping Blossoms/Fruit
Sudden heat, or extended temperatures above a certain heat, can have disastrous effects on plants. Some, like peppers or tomatoes, may lose their flowers. Others might be stunted in their growth or be unable to germinate at all.
Leaf Drop
Plants that have experienced stress, often in the form of high heat, will drop their leaves as a way to conserve water.
Insects
Insects are often a byproduct of heat waves. As temperatures stay high for extended periods of time, wildlife—in the form of bats, bees, and birds—seek shade. This can quickly boost insect populations in your garden or yard.
High Heat Solutions
Once heat has damaged a plant, it can be difficult to strengthen it again. Luckily, there are several preventative measures that can be taken to avoid damage. These include:
- Opt for plants that tolerate high heat or dry growing conditions.
- Improve soil condition. This is particularly useful to curb wilting. Ensure that soil has good drainage.
- Plant strategically. Plants that struggle in heat should be placed in locations that offer shade during the hottest parts of the day.
- Shade your soil. Mulch can provide insulation to plants whether the temperatures are too hot or too cold.
- Choose native varieties when possible. These are generally better suited for your climate.
- Utilize shade cloth to aid plants that are prone to bolting—like lettuce, radishes, and mustards.
- Water plants in the morning, rather than at night.
Ultimately, planning ahead is the best way to deal with summer heat. Learn to work with your environment—planting for shade, optimal soil conditions, and growing heat-tolerant plants for your climate—to enjoy the fruits of your hard work.
